The invention concerns an automatic multispindle turning lathe in which at least one cross-carriage carrying a tool holder is associated with at least one of the working spindles supported in a horizontally supported switchable spindle drum, each cross-carriage being movably guided in a guide body of a cross-carriage assembly provided on the bearing housing of the spindle drum.
In a known practical version of an automatic multispindle turning lathe of the initially mentioned type, the guide bodies of the individual cross-carriage assemblies carrying the cross-carriages form consoles built onto the bearing housing of the spindle drum. The cross-carriage assemblies are arranged symmetrically to the vertical, those for the lower working spindle pair being located in the horizontal plane and those for the center and upper working spindle pair being provided on each side in planes which are parallel to each other and in oblique position, the carriage assemblies being movable.
This type of carriage arrangement results in the cross-carriages being mounted partly on the underside of the bearing consoles of the cross-carriage assemblies, so that their turning tool holders must be suspended on the underside of these cross-carriages. This results in different working directions of the tools, which in turn requires different mounting positions of the latter on the turning tool holders, which is of particular disadvantage for a preadjustment of the turning tools (see the book "Automatic Turning Lathes" by Dr. H. Jager, p. 250).
In another machine design which is part of the state of the art, attempts have now been made to remedy the disadvantage resulting from the preadjustment of the turning tools by their different mounting positions by having all cross-carriage assemblies arranged at identical angular distances and in such a way that the path of tool displacement is located in planes passing through the respective spindle center and spindle drum center and the cross-carriages of the individual cross-carriage assemblies in the circumferential direction are each located on the same side of these planes. Although this measure allows the location of all turning tools in the tool holders at the same level, the cross-carriages in this design must also be provided below the consoles bearing them or in such planes that access to the tools of the rear lower as well as the front upper cross-carriage, for example, is difficult or unfavorable. Furthermore, this design makes it necessary to provide a cross-carriage in a zone of the machine working space where the chips drop down, with an unfavorable effect on chip removal.
The same disadvantages also exist with a cross-carriage arrangement according to German Utility Model Pat. No. 7,408,962, for it also requires a partly suspended arrangement of turning tools which not only requires different mounting positions but also results in difficult access to the tools and which requires the installation of a lower cross-carriage assembly in such a zone that the chips produced are hindered from removal from the working area.